SAN FRANCISCO (CBS 5 / KCBS) — The government’s star witness in the Barry Bonds perjury trial, longtime friend and former personal assistant Steve Hoskins, testified Wednesday about his knowledge of the home-run champion’s alleged steroid use dating back to 1999.

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Hoskins claimed that he first learned of Bonds’ supposed steroid use in conversations that he had with Bonds and his personal trainer, Greg Anderson.

Hoskins also told the jury in federal court in San Francisco that he saw Anderson leave Bonds’ spring training bedroom with a syringe in 2000 — although he admitted that he never actually saw Anderson give Bonds an injection and just assumed that the syringe contained steroids.

Bonds, 46, is accused of lying when he told a grand jury on Dec. 4, 2003 that he never knowingly received steroids, other performance-enhancing drugs or any kind of injection from Anderson.

Because Anderson has refused to testify, Hoskins has become the key witness in prosecutors’ bid to prove that Bonds did take steroids and other drugs and therefore lied to the grand jury.

Hoskins said that Bonds, while playing for the San Francisco Giants in 1999, instructed him to ask Bonds’ orthopedic surgeon, Arthur Ting, about the effects of a certain type of steroid.

KCBS’ Doug Sovern Reports:

Asked by prosecutor Matthew Parrella for Bonds’ exact words, Hoskins said Bonds told him, “Find out what this steroid does and what’s the side effects, and was it good or bad.”

Hoskins said he later gave Bonds a written report from the doctor, but he did not say what the report said.

He then testified that he saw Bonds and Anderson disappear into Bonds master bedroom “once or twice” at spring training in Arizona for three consecutive years beginning in 2000 – including the occasion on which he saw Anderson exit the room with a syringe.

Hoskins also testified that Bonds complained during one spring training season that he was sore from injections. The conversation was “just that steroids, the shots were making his butt sore,” he said.

Hoskins was a childhood friend of Bonds’ and traveled with him as an assistant until 2003. Hoskins testified that Bonds’ significant weight gain concerned him so much that he secretly recorded a conversation with Anderson about steroids so he could convince Bonds’ father, Bobby Bonds, that his son was using the drugs.

Bobby Bonds, a former baseball star himself, was suffering from cancer in 2003. Hoskins said he made the recording in front of Barry Bonds’ locker in March of that year “to show Bobby actually what really was going on.”

“That was the only way to prove it to him,” Hoskins said.

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Portions of that recording were played for the jury in federal court Wednesday afternoon.

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At one point on the recording, Anderson is heard discussing what prosecutors allege are designer steroids he supplied to Bonds. Said Anderson: “But the whole thing is … everything that I’ve been doing at this point, it’s all undetectable.”

Soon after the material was played for the jury, Bonds’ attorney Allen Ruby went to work trying to erode Hoskins’ credibility. Ruby accused Hoskins of planning to extort Bonds after the player severed business ties with Hoskins during a March 27, 2003, meeting.

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During cross examination, Ruby suggested the recording was not made in March—as Hoskins said—but was done after the business split, perhaps in April, because Hoskins and Anderson discuss Bonds’ slow start to the season.

Hoskins also said he secretly recorded conversations with Bonds’ doctor and business lawyer. Hoskins said his recording of Dr. Arthur Ting was made in late 2003 or 2004, in hopes of dissuading Bonds from using steroids.

“I was trying to tell Barry how bad the steroids and drugs actually were,” Hoskins said. “I was trying to convey to him from Dr. Ting and others how bad they were.”

Hoskins denied he was planning to extort Bonds with the Ting recording—after Ruby pointed out that Bonds and Hoskins had parted ways as business partners by the time of that recording, too, and weren’t getting along.

“I would want to help Barry then and would want to help Barry now,” Hoskins said, noting he has since lost the recording of Ting.

Hoskins also said he recorded a spring 2003 conversation he had with Laura Enos, Bonds’ business lawyer, to protect himself. Enos was at the meeting where Hoskins signed a document severing his business ties with Bonds.

Bonds, who set Major League Baseball’s single-season and career home-run records while playing for the Giants, is accused of four counts of false statements and one count of obstructing justice.

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