Germany's controversial former Chancellor Gerhard Schröder is receiving treatment for signs of burnout.

Schröder is "suffering from severe burnout syndrome with the typical signs of profound exhaustion and a pronounced lack of energy," Germany's DPA news agency reported citing his doctor's assessment.

The former chancellor, a member of the Social Democratic Party (SPD), signed himself up for clinical treatment on his doctor's advice, his lawyer Hans-Peter Huber told reporters from AFP and DPA news agencies.

Schröder's ties to Russia heavily criticized 

The 80-year-old former chancellor occupied the post from 1998 until 2005 and led Chancellor Olaf Scholz' center-left SPD from 1999 to 2004.

He enjoyed a friendly relationship with Russian President Vladimir Putin and was deeply involved with Russian state-owned energy companies after his tenure as chancellor.

Heavily criticized over his Russian ties, Schröder was due to be questioned by a parliamentary commission of inquiry in Germany's northeastern state of Mecklenburg-Western Pomerania last month, but he never appeared, citing illness.

The probe was over his role on the board of directors responsible for the construction of the Nord Stream 2 gas pipeline from Russia to Germany.

The pipeline never went into service, amid Russia's 2022 invasion of Ukraine. Later in the same year, Nord Stream 2 was damaged in underwater explosions in the Baltic Sea.

Following the Russian full-scale Ukraine offensive, Schröder was reluctant to fully distance himself from Moscow and Putin, which estranged him from Berlin's political establishment and from his own SPD party.

Edited by: Roshni Majumdar