Rolling Stone is reporting that the Tom Petty estate has accused an auction house of dealing in stolen property of the late singer, with the family announcing on Wednesday that it would pursue “swift legal action” against the Boston-based RR Auction.

The family didn’t specify what measures they plan on taking with regard to the allegations, but noted that they’re “pursuing all available legal action for the immediate return of these items,” further calling to avoid participating in the auction until the matter has been resolved. The items were allegedly stolen from a secured archive, the family said, and include some of Petty’s clothes, autographed items and limited editions. The family said the property could “easily be traced back to family members.”

“We believe RR Auction, headquartered in Boston, is offering stolen Tom Petty memorabilia with a completely false provenance inaccurate to fact and in complete denial of clear evidence they have been presented,” the family said in a statement. “They will not disclose the cosigner who has provided these items or how they were acquired. But they are clearly stolen, there is no other word for it.”

In a statement, RR Auction’s attorney Mark Zaid said the company “has been cooperating with the Petty family from the moment they reached out to us just days ago and will happily continue to do so without unnecessary hostile threats of litigation.” Zaid went on to claim that the company has always found resolutions in the rare instances when items’ ownership were in question. “We continue to diligently investigate this situation and have requested the Petty family to cooperate with us as well,” he said. “That said, we also take seriously any defamatory allegations against our company, which has developed a stellar reputation over the last half-a-century of auctions, many of which are often in the news.”

Read more at RollingStone.com.