Philadelphia (CNN) -- A former Whole Foods Market employee says he was fired because he is Muslim.
Glenn Mack Jr. told reporters Tuesday that he experienced harassment by his supervisors because of his Islamic faith, resulting in his termination.
A spokeswoman for the natural-food supermarket chain said the company denied Mack's allegations.
Mack, 24, started working for Whole Foods in 2008. He was terminated in February 2011 for absenteeism, said his lawyer, Amara Chaudhry, with the Philadelphia chapter of the Council on American-Islamic Relations.
He filed a complaint with the U.S. Equal Employment Opportunity Commission in March, Chaudhry said, adding she will file an amended complaint in the next few weeks.
Whole Foods Market spokeswoman Kate Lowery said the company "cannot give out details about current or former team members due to privacy, but we deny these allegations."
"It's well known that Whole Foods values and celebrates diversity," Lowery said, adding, "We have a zero-tolerance discrimination policy, zero tolerance."
Mack said he had been well-liked at the Whole Foods location on Pennsylvania Avenue in Philadelphia. He said he was the community service liaison and had been chosen to run the employees' assistance fund designed to help "team members in need." Mack added he was also selected to meet Whole Foods Market co-founder and CEO John Mackey.
The problems began, he said, after his supervisors learned he was using his approved vacation time for Hajj, the Islamic pilgrimage to the holy city of Mecca in Saudi Arabia during the last month of the Islamic calendar.
Hajj represents the fifth and final "pillar" of Islam. Every Muslim who is physically and financially capable is expected to make the pilgrimage once in their lifetime.
Mack said he had kept his Islamic faith a secret after overhearing comments that disturbed him. He said he requested time for the vacation two months in advance of the November 2010 trip. Prior to his vacation, his supervisors gave him a choice of keeping his job or going on the trip, he said.
Mack was downgraded from full-time employment to part-time employee upon returning from the pilgrimage and before being terminated, he said.
While working, he said he was followed by supervisors and watched when he went to pray in a storage room, and so began to complete his daily prayers outdoors near a trash dumpster.
"The fact that Glenn felt pressured or compelled to pray in the location that he did is not insignificant. A Muslim wouldn't do so unless under compelling circumstances or in a state of duress," Chaudhry, his attorney, said.
Whole Foods works with its employees to accommodate special requests and has an open-door policy, Lowery said, adding the company has many Muslim employees in the Philadelphia and Mid-Atlantic regions.
"We are looking at this from every angle possible," Lowery said.
A formal lawsuit has not been filed; however there is a pending matter before the EEOC and that has been cross-filed with the Pennsylvania Human Relations Commission, Chaudhry said. Mack is seeking reinstatement and compensation for his termination, plus mandatory tolerance training for employees, Chaudhry said.