Many albinos are living in fear of their lives
Tanzanian police say another albino man has been murdered - the 26th victim in the country in under a year.
The attackers reportedly severed the man's right foot and genitalia. His wife, also an albino, was also injured.
Witchdoctors want the parts for potions they say make people rich, reports BBC correspondent Vicky Ntetema.
In an undercover report last week, she was offered albino body parts by witchdoctors, who said their clients included police officers.
Jovin Majaliwa is reported to have been killed in his home in a remote Lake Victoria village after dark on Thursday - but police have only now released details of his murder.
The graves of albinos are often sealed with cement to prevent grave robbers
His wife, also an albino, was attacked but managed to raise the alarm. She is being treated in hospital.
Neighbours have asked the police to look after two of her children who also live with albinism.
Our correspondent's investigation revealed that witchdoctors are behind the killings. They use albino organs such as hair, arms, legs and blood to make potions which they claim make people wealthy.
The BBC has also obtained evidence that suggests the police are involved in the racket which is why it has been difficult to catch the culprits.
Mwanza Regional Police Headquarters, in the region which has the highest number of albino killings, reject the claims, saying that they are working with the community to identify the killers.
One hundred and seventy three witchdoctors have been arrested since March, when President Jakaya Kikwete had ordered a crackdown of all those involved in these ritualistic killings for riches.
But the minister was not able to give details about what had happened to them.