The family of a French actress, who was beaten to death by her rock star boyfriend, has called for a harsher jail sentence for her killer.
Cantat said he was deeply sorry for Trintignant's death
Bertrand Cantat, was given eight years for fatally beating Marie Trintignant, 41, in Lithuania last year.
Cantat, 40, lead singer with Noir Desir, had admitted killing her but said it was an accident.
Ms Trintignant's family filed an appeal against the sentence with the Vilnius District Court.
The family's lawyer, Kazimieras Motieka, said the court had mitigated Cantat's sentence, without serious grounds.
Mr Motieka said that under Lithuanian law the sentence should have been based on the average sentence - between the maximum and minimum sentence for a particular crime.
"Our laws provide that the count starts from the medium sentence, which in this case was 10 years of imprisonment, and allows it to be cut or increased if there are extenuating or aggravating circumstances," he told French news agency AFP.
"There are no such circumstances in this case in our opinion and that means that there is no reason to mitigate the sentence."
He said the appeal hearing could be held in a month's time.
The move comes on the last day for Cantat's lawyers to file their own appeal.
Cantat's lawyer Virginiijus Pairtis said he did not know what "games the other side is playing". He would not say whether he was going to appeal the original verdict.
The singer's lawyers had wanted a reduced charge of reckless manslaughter, which carried a lesser penalty.
Ms Trintignant's killing and Cantat's trial gripped France, where both are well-known personalities.
During the trial, the court heard that Cantat hit Ms Trintignant four times as they rowed in the Vilnius hotel last July.
Ms Trintignant, the daughter of French film star Jean-Louis Trintignant, fell into a coma and died five days later from swelling of the brain.
Cantat admitted slapping Ms Trintignant, but said he did not intend to kill her.
Nadine Trintignant, the victim's mother, has rejected Cantat's explanations, and labelled him a "murderer" in a book she wrote about her daughter.