A Tulsa, Okla, Police Captain is suing his Chief and the city after he was demoted and targeted by an internal investigation for refusing orders to attend an event featuring lessons in Islam, a tour and a prayer service at a mosque linked to an unindicted co-conspirator in a terror financial trial.

The legal action has been brought by attorneys with the Thomas More Law Center on behalf of Paul Fields.

Named as defendants are the city, Police Chief Charles W. Jordan and Deputy Chief Alvin Daryl Webster. WorldNetDaily's requests for comment did not generate a response from the defendants.

The lawsuit focuses on the officer's constitutional and civil rights, and besides a resolution of Fields' concerns, it seeks an injunction preventing "enforcement of defendants' unconstitutional acts, policies, practices, procedures and/or customs."

At issue is a solicitation by officials in the Tulsa Police Department for officers to attend a "Law Enforcement Appreciation Day" organized by the Islamic Society of Tulsa. The invitation said the officers would be given tours of the mosque, meet the mosque's leadership, be given presentations of "beliefs, human rights, women" and "watch the 2-2:45 weekly congregational prayer service."

While at first the police administration's recommendation for attendance at the event appeared to be voluntary - there was a voluntary signup list - the law firm said when officers refused to respond, the managers made it a required event.

The day "had nothing to do with any official police function. It clearly fell outside of the police department's policy on community policing, and based on comments made by police department officials in a closed door meeting, it was not ‘community outreach' as it has been previously portrayed," the law firm explained.

Rather, it included a mosque tour, meetings with local Muslims and Muslim leadership, observing a ‘weekly prayer service,' and lectures on Islamic ‘beliefs,; " the Thomas More Law Center explained. "The event was scheduled for Friday, march 4, 2011 -Friday being he ‘holy day' or ‘Sabbath for Islam. In fact, the event was originally voluntary, but when not enough officers were willing to attend, it became mandatory."

The lawsuit alleges, "The event held by the Islamic Society involved Islamic proselytizing. The Islamic Society event was advertised as including Islamic proselytizing, and it in fact resulted in the proselytizing of city police officers who attended the event."

The issue of Islamic law, or Shariah, infiltration into the United States is drawing increasing attention. Several state legislative efforts already have developed, including in Oklahoma, Missouri, Tennessee and Florida, to prevent judges from applying Shariah, which includes penalties such as beheading for leaving Islam, in the government's court systems.

Last year in Oklahoma, voters with a 70-percent majority approved such a ban, but U.S. District Judge Vicki Miles-LaGrange blocked it after the Council on American-Islamic Relations argued the move was "anti-Islam."

The issue also is the subject of a lawsuit in Michigan, where city officials in Dearborn are accused of allowing Shariah to be used to block Christians from discussing their faith at the city-sponsored Arab Fest. Under Shariah, it is illegal for a Muslim to convert to another faith.

[This report is a WorldNetDaily Exclusive]