The brother-in-law of Spain’s King Felipe VI on Monday began serving a nearly six-year jail sentence for fraud and tax evasion, AP reported. Inaki Urdangarin arrived at a prison near Avila, about 100 km north of the Capital city of Madrid, in the morning, said an unidentified prison official.

The 50-year-old former Olympic handball medal winner is married to Felipe’s sister Cristina, and is the closest person to the ruling Bourbon family to be imprisoned. He was sentenced to five years and 10 months in prison last week after being found guilty in February 2017 of using royal connections to overcharge regional governments for staging sports and tourist events, Reuters reported.

Urdangarin challenged the original ruling by a court in Mallorca in the Supreme Court, which slightly reduced his sentence and overturned a part of it. He may now file an appeal against the top court’s ruling before the Constitutional court.