Clemens' agent, Randy Hendricks, and Astros' owner Drayton McLane also denied the report.
Newsday reported on its Web site that Clemens had decided to re-sign with the Astros and an announcement would be made as soon as Tuesday.
Purpura denied the report, telling ESPN.com's Jayson Stark, "It's status quo, except for all the media attention we've had."
"We've had no conduct with Roger's people today," said Purpura, adding that the last time he talked to Hendricks was Sunday.
Purpura said he was told then that "Roger was still in the mode of trying to decide what he wants to do." So essentially, Purpura said, "We're just awaiting his decision."
Hendricks told ESPN.com that he hadn't spoken to the Astros on Tuesday.
"Contrary to Newsday, there is no agreement with the Astros," Hendricks said.
McLane also reiterated that Clemens has not signed with the team.
"We haven't finished the deal yet," McLane told the Houston Chronicle. "We've been standing by. Tim or I have talked to him every two or three days. They haven't given us a decision. They haven't said a word to us about it. That's complete news to me. We haven't finalized the deal yet nor has he told us. Boy, that's total news to us."
Still, McLane remains optimistic that a deal will get done soon.
"I've been confident since January," McLane told MLB.com. "We waited on them and they said they would get back to us. I talked to Tim about an hour and a half ago. We're very, very optimtistic, but we knew that we have to wait to hear back from them. That has not happened yet."
Another baseball executive, whose team has been involved in the Clemens discussions, told Stark on Tuesday that he believes Clemens could sign with the Astros in the next 48 hours. Among the reasons: Clemens' son, Koby, is about ready to come off the disabled list in the Astros' minor-league system, making it possible that Clemens could pitch to Koby in his tuneup starts, either in extended spring training or for one of the Astros' minor-league clubs.
A source who has talked to Clemens this month said Clemens spoke about that possibility and seemed intrigued by it. Father and son have been working out together recently as they both geared up for a return, the source told Stark.
Meanwhile, two baseball men who have been in contact with Clemens told Stark the only other team Clemens is seriously considering is the Red Sox, because they are more willing than the Yankees to give Clemens the kind of schedule and travel concessions the Astros offered him over the last two years. Nevertheless, Houston is still viewed as the favorite. Texas has also been considered a possibility, although owner Tom Hicks was told last week by Hendricks that the Rangers were out of consideration, GM Jon Daniels said.
"Tom got the call on Friday that we were no longer in the running for his services," Daniels told The Associated Press on Tuesday. "The way we looked at it was, it would be an honor to be associated with him but we've continued to focus on the 25 guys here. It would have
been nice, but we weren't planning on it from the get-go."
The Astros were 27-26 and 6½ games behind the NL Central-leading Cardinals after Tuesday night's 6-3 victory over St. Louis.
Pitcher Andy Pettitte said after the game that he knows what's going on "but it's not my place to say anything about that, really."
"I've been talking to Roger and I'll leave it up to him to let him share whatever he's going to share, whenever it's time to share it," Pettitte said.
In the Houston clubhouse at Busch Stadium, Clemens was a big topic of discussion.
"False alarm," manager Phil Garner said. "I didn't see it, but one of the players came in and told me that it was on TV that we had signed him.
"I just talked to our GM when we heard that it was on TV and he has no news of it and he would be the guy that would know," he said. "We've said all along that we'd love for him to sign here. We think this is the right spot for him and we think it's a good home."
Craig Biggio would love to have Clemens back on the team but said he'd prefer to wait for an official word.
"I talked to somebody today and talked about a supposed teammate that was not a teammate, so let's just see whatever happens," Biggio said. "Wait 'til it's done and go from there."
In December, the Astros declined to offer Clemens arbitration after he went 13-8 with a 1.87 ERA in 32 starts. However, Clemens began to wear down late in the season and lasted just two innings in Houston's Game 1 loss to the Chicago White Sox in the World Series with a hamstring injury.
Clemens last pitched competitively in the World Baseball Classic, where he beat South Africa for the United States in the first round and lost to Mexico 2-1 in the second on March 16.
In his two seasons with the Astros, Clemens posted a 31-12 record with a 2.43 ERA.
An 11-time All-Star, Clemens has more wins than any other living pitcher and ranks ninth all-time with 341 victories. In 672 career games, he is 341-172 with a 3.12 ERA and has recorded 4,502 career strikeouts, trailing only Nolan Ryan (5,714) on the all-time list.
Information from The Associated Press and SportsTicker was used in this report.