Gay death mystery of head who met Diana.
Casey McCann, 57, choked to death lying in his underpants with his hands and feet lashed together by his own necktie.
Police last night launched a murder inquiry and are looking for a man seen with him shortly before he died.
Mr McCann took over the prestigious English-speaking St Paul's School in Sao Paulo, Brazil, 10 years ago after teaching in Kent.
The Prince and Princess of Wales met him in April 1991 when they toured the country. After showing the royal couple around Mr McCann said: "I thought they were marvellous, so natural and friendly."
Neighbours in the exclusive Jardim Europa district where Mr McCann lived said he often received visits from young men.
Cafe owner Hailton da Silva Santos said: "A lot of times he came in here with a tall, strong guy with dark hair, aged about 30.
"He also came in with a youngish black guy."
When asked about his gay lifestyle neighbours said he did not speak the local language and seldom went out.
Police say the suspect left a shirt in the apartment.