Salim Mehajer is not the only member of his family capable of capturing attention.

Just days after it was revealed the suspended deputy mayor of Auburn was being investigated over domestic violence allegations, he was all smiles at the Miss Lebanon Australia beauty pageant where his sister, Mary Mehajer, took the winner's crown.

Mr Mehajer took to Facebook to congratulate his sister, who outclassed eight other contestants in the charity fundraiser aimed at celebrating the achievements of young Lebanese Australian women.

Organiser Joseph Khoury​ said judges were faced with a difficult task in choosing a winner at the spectacle, held before a crowd of 600 at Doltone House in Pyrmont.

"All the girls were very nice so it was a difficult decision for the judges to appoint a winner," he said.

Mary Mehajer​, who studies at the University of Technology, Sydney, won the title of Miss Lebanon Australia 2016, with Mary Hakim the first runner up and Jessica Nercessian the second runner up.

The big night out for Mr Mehajer and his family follows a report last week that police were investigating allegations about an altercation at the Wollongong home of the sister of his wife, Aysha Mehajer.

The revelation comes after ongoing speculation about the couple's union, sealed in a now infamously lavish ceremony last year.

Mr Mehajer has repeatedly reasserted his adoration for his former beauty therapist wife following the speculation.