A man accused of posing as an Uber driver and sexually assaulting two women he picked up in Brisbane's nightclub precinct allegedly thanked one of his victims and gave her a bottle of water after attacking her.

Police allege the 41-year-old, who cannot be named for legal reasons, drove his black SUV into Fortitude Valley on two separate nights in September and told both women he was their driver for the ride-sharing app.

One of the women questioned why the app had not registered his car and he allegedly told her the booking had been cancelled and she could pay cash.

Court documents revealed that during the trips the man had complained to both women that he had trouble meeting people.

They also revealed that after allegedly assaulting one of the women, he tried kissing and hugging her and that he made the second woman pay $30 for her trip after he assaulted her.

The man has been charged with four counts of sexual assault and one count of deprivation of liberty after detectives searched his Carindale home on Friday.

Police said investigations at this stage had not revealed any link between the man and any legitimate ride-sharing app.

The man faced the Magistrates Court in Brisbane on Saturday, where his lawyer did not apply for bail.

Police said they feared the man may have assaulted other women and urged anyone with knowledge of similar offences to contact authorities.

The case will return to court in November.