Botha said he was told some police officers were offered R453 625 and others were offered between R2 000 and R5 000 a few days after the Valentine's Day shooting.
"I then realised that [the door] was not safe and that it should be sent away otherwise it would have impeded the case of both sides," Botha said.
He said the door needed to be removed as evidence and for forensic tests to be conducted anyway.
Pistorius stands accused of murdering Reeva Steenkamp in his Pretoria home on the morning of February 14.
In an affidavit submitted as part of his bail application, Pistorius said he thought he was shooting at an intruder, through a closed bathroom door.
He was granted R1-million bail on Friday, February 22. He was allowed to pay an initial instalment of R100 000, with the balance due by March 1.
Pistorius is to challenge his bail conditions as unwarranted and unfair, according to a report on Friday night.
His lawyers would seek to have several of his bail conditions scrapped or altered, eNCA reported.
Pistorius' next court appearance is on June 4.
Meanwhile, the parents of Steenkamp are considering a civil claim against Pistorius, a family lawyer said on Friday.
"The nature and the extent of the relief to be sought [by Barry and June Steenkamp] still has to be determined," attorney Mike Venter said.
Steenkamp was cremated in a private ceremony in Port Elizabeth on February 19.