There is much about Freemasonry that remains shrouded in mystery to the outside world. But a group of members in the US state of Georgia appear to have clarified one thing - the supreme being in which all Masons are required to believe is not likely to be black.

Freemasonry lodges in Georgia are at loggerheads over the admission of a "non-white" member to an organisation that was founded on the principles of the Enlightenment but which is apparently still struggling to catch up with the latter part of the 20th century.

Now the issue is headed for a Masonic trial and the state courts after some lodges in Georgia sought to revoke the charter of one in Atlanta for admitting Victor Marshall, a 26-year-old African-American army reservist, last autumn.

The Atlanta lodge has fought back in the state courts by seeking to block the move on the grounds that is based on "racial animosity and hatred".

The row blew up after Marshall attended a celebration in Savannah in February to mark the 275th anniversary of a lodge in the city. Although there are other Masons of colour in Georgia, including Asians and Hispanics, some members were disturbed to encounter a black man and laid a complaint that he did not belong.

"There were ill-informed brethren who were surprised that there was an African-American brother," David Llewellyn, a Freemason and lawyer for the Atlanta lodge, told the New York Times, "and some of them were very upset".

The stipulations to join the Masons are that members must be male, not slaves, of good character and have faith in a supreme being but no mention is made of racial origin.

The grand master, or leader of the Masons in Georgia, J Edward Jennings Jr, sent an email to members saying that Marshall was a legitimate member and should be treated as such. But that did not quell the row.

Under pressure, Jennings agreed to convene a Masons court to hear a complaint against the head of the Atlanta lodge, Michael Bjelajac, who is accused of violating "moral law", the "ancient landmarks" and "immemorial usages" of Freemasonry by admitting Marshall.

But the complaint has met with ridicule in part because there are largely black Masonic lodges in the US as well as in African countries such as Ghana.

The objections to Marshall's membership have been led by Douglas Ethridge and Starling Hicks, both worshipful masters of their respective lodges in Georgia who have both declined to be interviewed.

In court papers, Llewellyn said that when he called Etheridge to discuss the lawsuit, the Mason replied, "To hell with you, buddy", and hung up.

Freemasonry in the US has a long history of segregation. A black stream of the organisation, known as Prince Hall Masons, was only recognised by mainstream Masons in 1990 and even then several states, including Georgia, refused to do so.

The Grand Master of the Prince Hall Masons in Georgia, Ramsey Davis, told the New York Times that he approached the mainstream leaders in the state to discuss recognition but was rebuffed.

"There's deep-rooted racism in the leadership," he said. "I've had many calls from white Masons to say they cannot understand why things are this way."

Marshall told the Associated Press that while he is disillusioned by the attitudes of some of his fellow Masons he has not lost faith in the organisation.

"I hope we'll be victorious and that Freemasonry will come out in a more powerful light," he said. "But of course sometimes the bad side can overwhelm the good side."