Former News of The World editor-in-chief Hall is representing Iranian consortium head Kia Joorabchian.
But he also advises the East London club via his agency Phil Hall Associates, which was appointed last year (PRWeek, 9 September 2005).
Hall explained: ‘We draw a line in the sand and make sure no problems arise. I help both sides independently with press and media only.'
Separately, Eggert Magnusson, the Icelandic businessman also eyeing up West Ham, used Holborn PR to advise on communications surrounding his own approach for the club last week.
Holborn chairman David Bick worked with former Football League chairman Keith Harris, who is advising the bidder and is now executive chairman of investment bank Seymour Pierce.
Bick declined to comment.