Amarinder Singh - the former Punjab Chief Minister - is the first major political leader to condemn the vigilante killing of two men over claims of religious sacrilege at gurdwaras in Amritsar and Kapurthala.
Mr Singh called the murder of the two men "illegal... absolutely unacceptable".
"Sacrilege is wrong but it is also wrong to kill a person. What is this way? There is the law. If you take the accused to the SGPC (Shiromani Gurdwara Parbandhak Committee, a pan-national organization responsible for the management of gurudwaras) office, interrogate and kill him... Is this the way? This is illegal and this is absolutely unacceptable," the ex-Congress leader was quoted by PTI.
"There is no justification for mob lynching whatsoever... it is condemnable," Mr Singh said.
Asked if the killings were a sign of frustration within the Sikh community over unresolved tension related to the 2015 sacrilege incidents, Amarinder Singh defended his track-record in the matter.
He said the state (when he was Chief Minister of the ruling Congress government) first had to fight a long legal battle to get the inquiry back from the CBI... when the investigation started 22 people, including police officials and civilians, were arrested (but they) are on bail now.
Two men - whom police have not yet identified - were killed by mobs at Amritsar's Golden Temple and a gurdwara in Kapurthala after allegedly desecrating Sikh religious sentiments.
Questions have been raised over the police's handling of each case, particularly after withdrawal of a statement announcing a FIR had been filed in connection with the killings.
Questions have also been raised over the lack of political leaders speaking out against the deaths.
The shocking murders have, so far, drawn muted (at best) reactions from the ruling Congress and major opposition parties - the BJP, the Aam Aadmi Party and the Akali Dal - with everyone reluctant to condemn the deaths for fears of a backlash from voters in elections due in a couple of months.
Congress MP Rahul Gandhi did tweet on Tuesday - he attacked the BJP saying "before 2014 the word 'lynching' was practically unheard of', but stopped short of naming the Punjab killings.
Mr Gandhi's tweet triggered a vicious counter-attack from the BJP's Amit Malviya.
SGPC President Harjinder Singh Dhami was more straightforward. "It is related to the Guru Granth Sahib and not just any social offense. We cannot bluntly condemn..." he told NDTV on Monday night.
Sidhu, meanwhile, has been more direct, but in calling for "public executions" for those accused of religious sacrilege; it is unclear if he was referring to people simply accused of such a crime or those found guilty after being tried in a court of law.
Punjab Deputy Chief Minister has called for stricter punishments - but again for those who are found guilty of religious sacrilege. He made no reference to punishments for those involved in mob killings.
Amarinder Singh quit as Chief Minister last month after a protracted and bitter verbal war with rival (and now Congress state unit boss) Navjot Sidhu.
Much to the consternation of his former party, Mr Singh, a veteran politician, has floated his own party - the Punjab Lok Congress - and announced a preliminary deal with one-time arch-rivals BJP.
With input from PTI
