The former chief financial officer of one of the world’s leading political strategist firms, the C|T Group, has been charged with defrauding the company of $850,000.

Mohammed Saderuddin Syed, 44, held a senior role within the C|T Group, the firm founded by Sir Lynton Crosby and Mark Textor that has helped conservative parties win office in the United Kingdom and Australia.

Syed ran the firm’s finances, and was based out of its Sydney office until leaving the C|T Group in January.

Police began investigating Syed over the alleged fraud last month.

On Wednesday, he was arrested and charged with four offences of dishonestly obtaining financial advantage by deception.

Details of the alleged fraud are yet to emerge, but police say it was worth $850,000.

“In February 2019, officers from Sydney City Police Area Command commenced inquiries into the alleged fraud of more than $850,000 by an employee of a research company,” police said in a statement.

Syed fronted the Day Street police station in Sydney on Wednesday, and will appear in the NSW local court next month, according to police.

He has surrendered his passport and will be banned from approaching airports or other international departure points. Syed will be required to find someone to provide a $100,000 surety, which will be forfeited if he breaches bail.

The C|T Group helps run campaigns and provides advice to the Liberal party in Australia, and has helped the UK Conservative party on its last four general election campaigns.

Crosby, one of its founders, was knighted by the former UK prime minister, David Cameron.

A spokesman for the C|T Group said it was aware of the Syed case, and was working closely with police. The company would not comment further.

“C|T Group Australia understands that NSW Police have charged one of its former employees, Mohammed Syed, with a number of charges of dishonestly obtaining a financial advantage for himself,” the spokesman said. “C|T Group has worked and will continue to work closely with NSW Police in respect of their investigation but will not comment further while the matter is before the Courts.”

Last week, the Guardian revealed the existence of a sophisticated campaign run by the C|T Group for Glencore, one of the world’s most powerful mining giants. The campaign, now terminated, was designed to boost public and government support for coal.

Similar strategies were pitched by C|T Group to a Qatari opposition leader for a project aimed at moving the Qatar 2022 football World Cup.