China Resources, the state-owned conglomerate whose chairman was detained last week by anti-corruption investigators, has allocated many of its investment banking deals over the past five years to institutions employing the chairman’s alleged mistress.

From 2009 until 2012, Credit Suisse was one of the most prominent advisers on acquisitions and capital market activity carried out by China Resources and its numerous subsidiaries, according to data from Dealogic financial services information. This period coincides with the employment of Yang Lijuan, who also goes by the name of Helen Yang and is alleged to have been the mistress of the disgraced China Resources chairman Song Lin.

But since Ms Yang left Credit Suisse and joined UBS in 2012, Credit Suisse has not advised on a single China Resources deal, according to Dealogic records.