Brisbane police are coordinating a search for a man possibly missing in the Brisbane River.

Police were contacted last night by a member of the public after she observed a man, possibly aged in his early 20s, enter the river at the West End ferry terminal in Orleigh Park at around 9.15pm (Saturday, December 14).

She watched the man as he swam towards Indooroopilly before losing sight of him when he was about half way across. The woman notified police when she failed to see the man exit the river.

Police conducted patrols of the riverbanks last night as well as monitoring missing person reports and conducting enquiries.

Brisbane Water Police and SES boats have searched the river and police patrols of the riverbanks have continued.

Patrols of the river will continue.

No missing person reports matching the man have been received.

The man is described as possibly aged in his early 20s, with a dark complexion, black hair and beard, approximately 185cms tall and was wearing black shorts, a black and white striped shirt and carrying a backpack.

Anyone who believes they know a man matching this description and who could have been in Brisbane last night is asked to check-in with that person and immediately contact police if they cannot be located.

If the man who entered the river from the West End ferry terminal last night is reading this release he is also asked to immediately contact police.

If you have information for police, contact Policelink by providing information using the online suspicious activity form 24hrs per day at www.police.qld.gov.au/reporting.

You can report information about crime anonymously to Crime Stoppers, a registered charity and community volunteer organisation, via crimestoppersqld.com.au 24hrs per day.

Quote this reference number: QI1902495652 within the online suspicious activity form.