The mining arm of Israeli billionaire Beny Steinmetz's business empire has launched a legal challenge against the UK home secretary and anti-corruption agency – in the latest twist to investigations into whether the company paid bribes to win a multi-billion-dollar iron-ore concession in Guinea.

BSG Resources is suing Theresa May, the home secretary, and the Serious Fraud Office (SFO) over their decisions to assist the Guinean authorities in the west African nation's investigation into how BSGR secured rights to the coveted Simandou iron-ore deposit.

The judicial review claim, filed last month in London’s high court, is the first public confirmation that the SFO has demanded BSGR’s agent and lawyers hand over documents related to the company.

BSGR is challenging so-called section two notices from the SFO, which were first issued in July, then reissued in October, and is seeking an order to have them quashed. The notices demand disclosure of documents, other than those protected by the privilege covering advice that law firms give their clients or papers prepared for litigation. – Copyright The Financial Times Limited 2014