Police in Egypt have been accused of beating a teenager to death and dumping his body in a canal.
The family of Ahmed Shaaban, 19, claims he was tortured by policemen from a station in Alexandria already implicated in the death of another young man, Khaled Said.
Two officers are being tried in connection with that death.
The authorities say Mr Shaaban committed suicide but his family says his body showed clear signs of torture.
A spokesman for Egypt's interior ministry has refused a request for comment from the BBC's Arabic Service. He accused the BBC of peddling lies and propaganda in reporting the allegations.
The case has emerged two weeks before Egyptian parliamentary elections, seen as an important indicator for presidential elections in late 2011.
In a video posted on YouTube, Mr Shaaban's family says he was on his way home from a friend's wedding earlier this month when he was stopped at a police checkpoint. They say there was an argument when he refused to be searched, and that he was arrested and taken to a police station.
The family says they were not allowed to visit him for three days. They then received an anonymous phone call, saying that the teenager's jacket and mobile phone were found in the Mahmoudia canal.
The next morning, the morgue authorities contacted the family, asking them to identify Mr Shaaban's body. The family says that his eyes were dark blue and that his stomach and arms were "ripped open", among other alleged abuses.
A lawyer for the young man, Ahmad Qutb, has dismissed official claims that he took his own life.
"There are photos and evidence [that] confirm that he did not commit suicide," Mr Qutb said, adding that a preliminary investigation suggests that he was tortured and pushed or thrown in the lake.
"We are not accusing anyone officially right now, but we need [an] investigation to identify the criminal," he added.
The police station where the alleged torture took place, Sidi Gaber in the port city of Alexandria, is the same one that was implicated in a police torture scandal concerning Khaled Said.
Witnesses say the 28-year-old died after he was dragged out of an internet cafe and beaten up. The government says he swallowed a packet of drugs and choked.
His death has become a rallying point against police brutality for Egyptians.