Former Sean Combs assistant Capricorn Clark testified that work was not yet complete on the then-new corporate headquarters of Bad Boy Entertainment at 1710 Broadway in New York City when she was allegedly taken there in 2004 by a bodyguard nicknamed Uncle Paulie and locked inside.

Clark told the court that she was taken to the “dilapidated” sixth floor, which she said was empty save for a folding table and chairs in the middle of the space.

“There was a heavy-set gentleman who was chain-smoking cigarettes and drinking black coffee,” Clark testified. “Very wide, very heavy, the size of two linebackers.”

Clark, seated in the witness box with her hair pulled back and wearing glasses, testified that she was “petrified” in that moment. She told the court that the bodyguard told her that she “had been brought to the building to take a lie detector test to figure out what happened" to some jewelry that had gone missing.

If she flunked the test, she testified the man told her, “They’re going to throw you in the East River.”

Clark testified that Combs had given her “three pieces of very high-end jewelry that were out on loan” before a private plane ride to Miami. At Teterboro Airport in New Jersey, Clark said she realized the jewelry had gone missing.

“Had you stolen the jewelry?” prosecutor Mitzi Steiner asked.

“I did not,” Clark responded

Clark told the court that the bodyguard named Uncle Paulie took her to the same location inside 1710 Broadway on five consecutive days, where she allegedly was administered lie detector tests.

“I wanted to prove my innocence. I didn’t like the threats,” Clark testified.

When she was allowed to return to work, Combs never mentioned the lie detector tests or inquired where she had been, Clark told the court.

The third week of testimony in the Sean Combs sex trafficking trial will begin today with testimony that the prosecution will present to try to help support the alleged kidnapping and arson elements of the racketeering conspiracy to which Combs has pleaded not guilty.

Federal prosecutors have said Combs’ former assistant, Capricorn Clark, was twice held against her will, including when she was allegedly forced from her apartment and into a car to take Combs and one of his bodyguards to the home of Scott Mescudi, the rapper better known as Kid Cudi.

Mescudi testified last week that Clark called him from a car to say that Combs was in his house. Nothing was taken, Mescudi told the court, though he said he found that Christmas presents were unwrapped and his dog was locked in a bathroom.

Combs allegedly forced Clark to take a lie detector test to prove she was not part of a robbery, according to the testimony last week of another former Combs personal assistant, David James.

Mescudi testified last week about alleged arson, which is another element of the alleged RICO conspiracy with which Combs is charged. Mescudi testified that he suspected Combs played a role in his car being set on fire with a Molotov cocktail.

Los Angeles Fire Department arson investigator Lance Jimenez is expected to testify today about what he found when responded to the scene of the car fire.

Combs is seated at the defense table in dark-colored pants and crew neck sweater. He embraced defense attorney Brian Steel upon entry into the courtroom and then greeted his other lawyers with hugs and smiles.

Catch up on everything from week 2 of the Sean Combs trial, including testimony from rapper Kid Cudi.

Read more here.

The third week of the trial of Sean "Diddy" Combs will resume in New York City on Tuesday, with witness testimony set to continue.

When court resumes on Tuesday, federal prosecutors plan to call Combs' former assistant Capricorn Clark and representatives from Los Angeles fire and police departments.

Across two weeks of testimony in Combs' sex-trafficking and racketeering trial, federal prosecutors called 16 witnesses, attempting to prove the rap mogul embraced violence and threats to coerce women into sex and protect his music empire.

Among those who have already taken the stand are musician and Combs' ex-girlfriend Cassie Ventura, her mother Regina, Combs' former personal assistants David James and George Kaplan, plus rapper Kid Cudi whose legal name is Scott Mescudi.

Combs has pleaded not guilty and denies sexually assaulting or trafficking anyone. Combs' lawyers have argued that the rap mogul's domestic violence was driven by jealousy and drug addiction, and that his voyeuristic sexual activities, while not mainstream, are his private business and do not amount to sex trafficking.

-ABC News' Peter Charalambous, Aaron Katersky, Josh Margolin, Tonya Simpson and Kaitlyn Morris