Glencore CEO Ivan Glasenberg is presented with the Person of the Year award by Lakshmi Mittal at the 2013 FT ArcelorMittal Boldness in Business Award ceremony FT flickr account

Glencore CEO Ivan Glasenberg is presented with the Person of the Year award by Lakshmi Mittal at the 2013 FT ArcelorMittal Boldness in Business Award ceremony FT flickr account

Glencore is the Swiss-based FTSE 100 miner that goes where others fear to tread. The hunt for higher returns hasn’t obviously paid off--the 2011 flotation price of 530p hasn’t been seen since--but the company’s appetite to operate in countries such as the Democratic Republic of the Congo (DRC) is undimmed. It’s what chief executive, Ivan Glasenberg, and his crew do. The stock market has just had to learn to price the risks.

It struggled in that task on Tuesday after Glencore said it had received a subpoena from the US justice department (DoJ) to produce documents relating to its operations in DRC, where it has two copper and cobalt mines, and also in Nigeria and Venezuela, where it trades oil. The DoJ wants to know how Glencore has complied with bribery and money laundering statutes and is looking as far back as 2007. At one point, the share price fell 12%, before closing 8% lower.

The market’s confusion is understandable. Some DoJ requests for information go nowhere. But this demand has arrived at such a delicate moment it is hard to believe the timing is co-incidental. Less than a month ago, Glencore settled a long-running dispute in DRC with its former partner Dan Gertler, an Israeli billionaire on whom the US imposed sanctions last year. To keep control of its mines, Glencore resumed multi-million royalty payments to Gertler but thought it was safe to do so, from a sanctions perspective, because the payments would be in euros.

Would the US authorities really tolerate that arrangement? Perhaps they would if bigger wheels were turning in the background. For example: if the US feared Glencore’s huge output in the DRC of cobalt, used in batteries, mobile phones and electric cars, could fall into Chinese hands while trade war threats are flying, would it privately smile upon the settlement?

That thought comforted investors--not least because Glencore said it had met with US authorities. But now the DoJ is the prowl anyway. Is it just reminding Glasenberg of its presence? Is it acting independently of the US Treasury? Could its subpoena be about something else entirely?

Those questions will hang in the air until facts emerge. As things stand, investors can only contemplate the alarming combination of controversial deal in the DRC and an unpredictable administration in Washington. It is reminder of why some fund managers have always regarded Glencore as un-investable.

By Nils Pratley