Washington: Upholding the religious freedom rights of Sikhs in the US armed forces, an American court has ruled in favour of a decorated Sikh Army Captain who had demanded that the military accommodate his articles of faith and abandon its impromptu discriminatory testing.

Captain Simratpal Singh, 28, in a lawsuit filed against the Department of Defence demanded the US military accommodate his articles of faith and dump the discriminatory testing.

"Thousands of other soldiers are permitted to wear long hair and beards for medical or other reasons, without being subjected to such specialised and costly expert testing of their helmets and gas masks," Judge Beryl A Howell swiftly ruled in Captain Singh's favour last evening.

The US Department of Defence, which had granted and then extended Captain Singh's temporary religious accommodation until March 31 this year, remains scheduled to make a final decision on Singh's permanent accommodation by that deadline.

Captain Singh, who is a West Point graduate, Ranger, and Bronze Star Medal recipient, has successfully passed the safety tests required of his unit.

"The US Constitution and the Religious Freedom Restoration Act make it crystal clear that Captain Singh's right to practice his faith and serve in our military are not mutually exclusive," said Amandeep Sidhu, Partner at law firm McDermott Will & Emery that represented Captain Singh.

"We are grateful that the court is on the right side of religious freedom with its ruling, which begs the question: does the world's largest employer really want to be on the wrong side of history?" he said.

The testing that the military planned to impose on Captain Singh is not required of any other soldiers, even the tens of thousands with medical or religious accommodations, and including previously accommodated Sikhs, he said.

Given that Captain Singh has passed the standard safety tests, further testing would clearly be discriminatory, he claimed.

"We have been advocating for the simple, straightforward, equal right to serve for years, and held onto the belief that the military would correct this injustice once they realized their mistake," said the Sikh Coalition's Legal Director, Harsimran Kaur.

"The military's treatment of Captain Singh, a decorated soldier, makes it clear that they deliberately want to squash diversity and religious freedom in their ranks; that is not something that any court, or American, should ever tolerate," Kaur said.

Last year, retired US Generals called on the US Department of Defence to eliminate the ban on observant Sikhs.

These generals joined US Senators, and national interfaith and civil rights organisations, who had previously signed letters in support of American Sikhs' right to serve.

"What is so sad about the Army's position in this case is how unnecessary it is," said Eric Baxter, Senior Counsel at the Becket Fund for Religious Liberty.

"Thousands of service members protect our country while wearing beards, including observant Sikhs. There is absolutely no evidence that there is any problem with providing a permanent accommodation so Captain Singh can continue to faithfully serve his country and Sikh beliefs," Baxter said.