FALL RIVER, Mass. -- An anonymous tipster who raised questions about a juror in the murder trial of former New England Patriots player Aaron Hernandez had a sexually explicit relationship with him, a prosecutor said in a filing released Monday, the day Hernandez's fiancée was seen wearing a wedding band.

Prosecutor William McCauley said an attempt by Hernandez's lawyer to question the tipster under oath is an "unwarranted fishing expedition." The woman's identity has been redacted in court documents.

James Sultan, one of Hernandez's lawyers, has said the woman called him anonymously several times after Hernandez was convicted in April of first-degree murder in the 2013 death of Odin Lloyd, who was dating the sister of Hernandez's fiancée. Sultan has said the tipster told him she worked with the juror and raised questions about what the juror knew about a 2012 Boston double-murder case in which Hernandez is also charged. Mention of that case was barred at the Lloyd murder trial.

Aaron Hernandez is serving a life sentence for the murder of Odin Lloyd and is charged in the deaths of two other people. AP Photo/Steven Senne

Sultan had acknowledged that the woman had extensive contact with Hernandez but said there was reason to believe she had relevant information.

But McCauley said in his filing that the woman wrote Hernandez sexually explicit letters before and during the trial and, believing in his innocence, wanted to continue their relationship after he was released. Hernandez subsequently destroyed the letters, McCauley said.

The woman's father served time in jail with Hernandez, McCauley said.

McCauley said the woman does not work with the juror as she claimed and that other things Sultan says she told him are untrue. McCauley also said Sultan has failed to provide information about the calls and the tipster.

Hernandez has a young daughter with Shayanna Jenkins, who attended the Lloyd murder trial sporting an engagement ring from Hernandez. On Monday she wore a gold wedding band along with a gold-and-diamond engagement ring on her left hand, The Providence Journal reported.

Jenkins petitioned a Rhode Island probate court to add the surname Hernandez to her name, matching the surname of their daughter, Avielle Jenkins-Hernandez. A judge said she needs more information before granting the request by Jenkins, who lives in North Providence, Rhode Island.

There is no record that Hernandez has gotten married or requested to get married since he was locked up, a prison spokesman said.

Hernandez, who grew up in Bristol, Connecticut, was sentenced to life in prison without the possibility of parole. He is awaiting trial in the Boston double-murder case and has pleaded not guilty.