Image copyright AP Image caption Juan Carlos abdicated last year to make way for his son Felipe 
 
 Spain's supreme court has agreed to examine a Belgian woman's claim to be the illegitimate daughter of ex-King Juan Carlos, who abdicated last summer. 
 
 Ingrid Sartiau says her mother had an affair with him in the 1960s, while he was married and a crown prince. 
 
 Royal officials said they respected the independence of the court, but refused further comment. 
 
 The case can only be heard because the king lost his immunity from prosecution after his abdication. 
 
 The court rejected a separate claim by Alberto Sola, born in Barcelona in 1956, who said his mother also had an affair with Juan Carlos. 
 
 But an official confirmed the case of Ms Sartiau, who was born in 1966 after Juan Carlos married, would be examined. 
 
 Juan Carlos, 77, will now have 20 days to respond to the suit. Ultimately, the former king could be asked to take a paternity test and the case could go as far as a public hearing. 
 
 He stepped down last June to make way for his son, Felipe VI, saying it was time for a "new era". 
 
 The two paternity cases had been rejected by the courts in 2012 while Juan Carlos still had immunity from prosecution. 
 
 Although parliament agreed to give the former him a level of immunity after abdication, it gave the supreme court the authority to prosecute him. 
 
 Image copyright AFP Image caption Juan Carlos was married to Sofia at the time of the alleged affair 
 
 Image copyright AP Image caption His daughter, Cristina, is facing a tax fraud trial 
 
 Juan Carlos was popular for much of his 39-year reign, and he was credited with helping his country's transition to democracy after the death of General Franco in 1975. 
 
 But his popularity, and his health, declined in his later years as the royal family was hit by a series of scandals. 
 
 He was dogged by numerous allegations of infidelities, and apologised after he was photographed hunting elephants at the height of Spain's financial crisis. 
 
 One of his two daughters, Princess Cristina, is currently facing a tax fraud trial over alleged links to her husband's business dealings. 
 
 Her husband Inaki Urdangarin is accused of embezzling millions in public funds with a former business partner. ||||| Story highlights A court will study a paternity lawsuit brought against the former King of Spain 
 
 A woman from Belgium alleges Juan Carlos had a relationship with her mother 
 
 Madrid (CNN) Spain's former King Juan Carlos, 77, will face a paternity lawsuit -- by a Belgian woman alleging that he's her father -- before the nation's Supreme Court, a 12-judge panel ruled Wednesday. 
 
 The court accepted the case for study, two court spokeswomen told CNN. 
 
 The royal household affirmed its "respect" for judicial decisions but declined further comment. 
 
 The plaintiff is Ingrid Sartiau, 48, who lives near Brussels. 
 
 Sartiau alleges that her mother and the married Juan Carlos had a relationship in late 1965, and she was born, as a result, in August 1966, said her attorney, Jaume Pararols. 
 
 He became Spain's King and head of state in 1975 after the death of the dictator Francisco Franco. 
 
 Juan Carlos abdicated in June in favor of his son, King Felipe VI, who was born in 1968. 
 
 While the court agreed to take Sartiau's claim for study, it rejected a separate paternity suit against the former King brought by a Spanish man. 
 
 For a paternity claim to be accepted, a petitioner must submit documentation, such as a photo or a letter, offering evidence of a relationship that involved Juan Carlos, the court spokeswomen said. 
 
 Sartiau's mother is alive and willing to testify, the lawyer, Pararols, told CNN by phone from his office in a town north of Barcelona. 
 
 "We would like to reach a settlement. My client never wanted it to get to this point," Pararols said. 
 
 The plaintiff has asked the court to require a DNA test for the former King, who has 20 days to make an initial response to the lawsuit. 
 
 Juan Carlos no longer has immunity from prosecution, but he has protection that permits cases against him to be heard only by the Supreme Court, which is Spain's second highest, after the Constitutional Court.
– Being an ex-king has its drawbacks, Spain's Juan Carlos has discovered. He enjoyed immunity from prosecution during his 39 years on the throne, but since he handed the crown to his son Felipe last year, two paternity suits have made it into the courts. One from a Spanish man was rejected, but the country's Supreme Court has agreed to hear a case from a 48-year-old Belgian woman who says the former king is her father, reports the BBC. Ingrid Sartiau claims that she is the product of an affair Juan Carlos had with her mother in 1965, when he was married but still a crown prince. Her lawyer tells CNN that Sartiau's mother is still alive and is willing to testify. "We would like to reach a settlement. My client never wanted it to get to this point," he says. The 77-year-old ex-king now has 20 days to respond to the lawsuit, and the court could require a DNA test from him.