A special Anti-Narcotics Court on Friday indicted former prime minister Yousuf Raza Gillani's son, Ali Musa Gillani, and 10 others in the ephedrine case which rocked the PPP government in March 2011.

The long-running case involves two Pakistani pharmaceutical companies, Berlex and Danas, that allegedly used political connections to obtain huge amounts of ephedrine and are suspected of diverting it to people in the drug trade who could have used it to make methamphetamine worth billions of dollars. The companies have denied any wrongdoing.

Along with Ali Musa Gillani, the accused include former health minister Makhdum Shahabuddin, health ministry official Abdul Sattar and Dr Abdul Khaliq.

Despite those accused maintaining their innocence, the judge formally charged the high-profile suspects of culpability in the ephedrine scandal.

Explore: Ephedrine scam: the case that wasn’t there

Ex-chief justice Iftikhar Chaudhry had pointed out in early 2012 that Ali Musa Gillani was also a suspect in the case.

The Anti-Narcotics Force (ANF) then issued a notice to Musa Gillani and one of his alleged 'front men' for manipulating the unauthorised allocation.

Today's hearing was preceded by a hearing on April 10, during which judge Irum Niazi expressed her intention to summon the accused to court if they refused to appear.

The next hearing has been scheduled for May 12, in which the accused are expected to present their arguments.

What is ephedrine?

Ephedrine, along with pseudoephedrine, is one of the main ingredients in methamphetamine, a scheduled narcotic substance.

Explore: Europe frets as cartels turn to S. Asia for ephedrine

Drug cartels often look towards countries with weak regulations to facilitate their requirement for ephedrine. According to Matt Nice of the Vienna-based International Narcotics Control Board, cartels look for a country with weak security and regulation “where you can obtain the chemicals because no one is paying attention, or it has never been a problem before.”

According to a UN report, published in 2015, "Increasing methamphetamine seizures and expert perception of high levels of methamphetamine tablet and crystalline methamphetamine use indicate the presence of a large and possibly expanding market in East and South-East Asia."

Methamphetamine, it is said, can be more valuable and addictive than heroine.