A former stylist for U2, Lola Cashman, has told the Dublin Circuit Court that items including a stetson and pair of trousers were given to her by Bono following the Joshua Tree tour in 1987.
U2 are seeking to retrieve a number of items which Ms Cashman tried to auction in 2002.
During his evidence earlier, Bono denied the band is suing Ms Cashman because she had written an unauthorised biography about them.
Bono said that the band had taken the action with great sadness.
"You may have wealth and power, but when someone is trying to push us around and blackmail us and threaten us with books, at a certain point you have to say "Stop right there", he said.
The case will resume on Wednesday morning.