Tuvalu's Human Rights Commissioner is lobbying New Zealand to drop what he describes as discriminatory immigration laws for disabled people.
Sa'aga Teafa has taken up the cases of two Tuvaluan families, who say they have been forced apart by tough medical requirements for New Zealand residence.
He said he had raised concerns with New Zealand Foreign Ministry officials.
One of those affected, Laasi Anderson, said her visual impairment meant she was unable to join her husband and daughter in New Zealand.
"They tell me that disabilities are not allowed there. I can't go with my husband, with my family because of my health."
Health requirements for residence visas in New Zealand, while considered on a case-by-case basis, are strict.
Applicants aren't allowed to impose undue costs or demands on the public health system.
Critics say this unfairly rules out people living with disabilities.
Laasi Anderson's story echoes that of Tavesia Valoaga, who has had to leave his disabled son Solomona Tavesia in Tuvalu.
Mr Valoaga said he had tried for several years to bring his son over to New Zealand but it was impossible because of his disability, which he declined to identify.
The general manager of Tuvaluan disability advocacy group Fusi Alofa, Melton Tauetia, said it was discriminatory to impose restrictions on migrants who lived with disabilities.
However, in a statement, a visa services manager at Immigration New Zealand, Michael Carley, refutes any claims of discrimination.
"Each application is decided on its own merits and the assumption that a decision is made due to any disability is purely speculation with no evidential basis."