Four of the 10 children seized in western Mexico as part of a child-trafficking investigation involving Irish couples show signs of sexual abuse, a Mexican official said Wednesday.

Jalisco state Attorney General Tomas Coronado said the children were examined by doctors but offered no other details.

"There are four children who show signs of having been abused (sexually), perhaps not in a violent way but there are signs (of abuse)," Coronado told reporters. He said he couldn't elaborate because of the ongoing investigation and didn't say when the alleged abuse would have taken place.

He said at least 11 Irish couples are involved in the case.

Fifteen Irish citizens have already talked to authorities, said Lino Gonzalez, a spokesman for Jalisco state prosecutors.

The foreign couples were giving 1,200 pesos, or $188, per week to the mothers since pregnancy, and paying for their medical attention. Then later the Mexican mothers would also be paid for allowing the children to stay with the couples while the purported adoption process proceeded, Coronado said.

"The great majority of the people from Ireland who have given their testimony have said they thought it was part of the adoption protocol in the state to be paying and that obviously means (someone was making) a profit throughout the adoption process," Coronado said.

Investigators are trying to determine if the Irish couples "acted in bad faith," Coronado said, or were being tricked.

The Irish Embassy in Mexico said in a statement it's providing consular advice to the couples involved.

About a dozen state police officers on Wednesday raided a two-story home in a middle class Guadalajara neighborhood that local media said belongs to the lawyers processing the adoptions. The lawyers apparently advertised in a local newspaper for expectant mothers who wanted to give their children up for adoption.

Prosecutors have said two attorneys who owned the law firm Lopez y Lopez Asociados are being sought in the case.

Coronado wouldn't identify the lawyers but said they have ignored prosecutors' requests to talk to investigators.

The apparent child-smuggling ring came to light last week when a woman told police that her sister-in-law was trying to sell one of her babies and "renting" the other one.

Investigators then detained the 21-year-old woman, who led authorities to three other women. Another three women who worked as nannies, the son of one of them and a taxi driver have also been detained, Coronado said.

Authorities seized the 21-year-old woman's two children, seven children from the Irish couples, and one from the nannies. The children are between two months and two years of age.

Agents found that the group was taking the woman's two children and others to a hotel in Guadalajara where they met with the Irish couples who believed they were going to adopt them. The couples then took the children to the nearby lakeside resort of Ajijic, where they were staying until the adoptions were finished, prosecutors said.

Roy Lahti, president of the condominium association of El Bosque gated community in Ajijic, said some of the couples had been staying there but that they had left.

Irish couples in the process of adopting Mexican children had been coming to the community of California-style homes and cobblestone streets for at least three years. They would stay between six and eight months and often the children lived with them, he said.

"They were really nice couples, always cordial," Lahti said. "The community here is shocked."