Autopsy rules out possibility that student was already dead when pushed into Tiber.

The results of an official autopsy cite drowning as the cause of death of Beau Solomon, the 19-year-old American student whose body was found in Rome's river Tiber on 4 July, according to Italian news agency ANSA.

The autopsy, published on 6 July, found water in Solomon's lungs which rules out the possibility that he was dead when pushed into the river.

The results came hours after Pope Francis met Solomon's parents before the usual Wednesday general audience. The news also follows newly-released evidence that two people accompanied Solomon from Trastevere to the Tiber embankment in the early hours of 1 July, the night the student went missing.

Witnesses allege they saw Solomon "drunk and staggering" near Ponte Garibaldi in the company of two people who then allegedly mugged the student. Witnesses also told police they saw a man being pushed into the river under Ponte Garibaldi in the early hours of 1 July.

On 5 July police arrested 41-year-old homeless man Massimo Galioto who is accused of pushing Solomon into the river and faces charges of aggravated homicide. Galioto has reportedly admitted an altercation with Solomon but claims that the student slipped into the Tiber. Galioto failed to raise the alarm and went back to sleep in his tent following his alleged crime, according to the news agency ANSA.

Police say there is no connection between Galioto and the pair who robbed Solomon of his credit card which was later used to run up charges of $1,700 in Milan. However, according to ANSA, police exclude a connection between the people who robbed Solomon of his credit card and Galioto although they are investigating homeless groups he associated with in Trastevere.

Solomon had been due to begin a summer course at Rome’s John Cabot University on 1 July but was reported missing by university authorities when he failed to attend the opening day.

When the body of the visiting Wisconsin-Madison student was found near Ponte Marconi on 4 July, four days after he went missing, it had a serious head wound, consistent with a fall.