A judge in Guyana has stirred controversy among human rights and trans activists by ruling on a 120-year-old law over crossdressing, stating it is only a criminal offence if it is done for an “improper purpose.”

Associated Press reports that on Sunday, a group called the Society Against Sexual Orientation Discrimination said the court’s decision was “dubious,” as it means police may still arrest crossdressers and trans citizens in the country.

They are to appeal the judgment, urging for the colonial-era statute to be removed from books altogether.

Human rights organisations called for an end to the crossdressing law back in 2009, following arrests and abuses of trans people citing the criminal acts of “wearing of female attire by man” and “wearing of male attire by women.”

The recent court decision, however, is barely a partial victory for trans activists in Guyana.

Quincy McEwan, director of Guyana Trans United, said the judge failed to define “improper purposes.”

He said: “The trans community is very worried and still fearful of arrests in light of this decision.”

Police have also been accused of randomly applying the crossdressing law while on patrol in Georgetown, the coastal capital.

In his decision on Friday, acting Chief Justice Ian Chang said people cannot be found in violation of the law if they are cross-dressing “for the purpose of expressing or accentuating his or her personal sexual orientation in public.”

He said police failed to inform the litigants the reasons for their arrests and awarded them compensation.

The law survived constitutional reforms in 1966 and 1980, so Mr Chang argued that changes must come from the legislature rather than the judiciary.

Zenita Nicholson, a board member with the Society Against Sexual Orientation Discrimination, said the court “lost a golden opportunity” to eliminate discrimination.

She said transgender citizens “will continue to be vulnerable to human rights abuses with this dubious decision.”

In February 2009, police in the Guyanese capital, Georgetown, arrested and charged seven people under section 153 (1) (xlvii) of the Summary Jurisdiction (Offences) Act Chapter 8:02, which criminalises as a minor offence the “wearing of female attire by man; wearing of male attire by women.”

The detainees said that police refused to allow them to make a phone call or contact a lawyer, both basic rights under Guyanese law.

They told human rights organisations that police officers photographed them and then told them to take off all of their “female clothes” in front of several police officers.

One defendant said that after the detainees stripped, the police told them to bend down to “search” them, as a way to mock them for their sexual orientation. They were then ordered to put on “men’s clothing.”

Last year, authorities in Guyana started planning a series of public consultations on whether to repeal the country’s anti-gay laws.

Guyana remains the only country in mainland South America with laws forbidding homosexuality on its statute books, though they are said not to be enforced.