NEW DELHI — Prison officials in the Indian capital have given Delhi Chief Minister Arvind Kejriwal an insulin jab after his sugar level shot up, his party told the BBC.

Kejriwal has been held in Tihar jail since his arrest on 21 March.

The authorities accuse the former anti-corruption crusader of being involved in a money laundering case — he has denied the charges.

His arrest just weeks before India began voting in a general election shocked many Indians.

Critics say the action against Kejriwal and several other opposition parties in the run-up to the election is politically motivated and denies them a level playing field in the parliamentary election. The Indian government says the investigative agencies are just doing their work.

Kejriwal, whose pre-trial detention was extended by a fortnight on Tuesday, is a diabetic and his detention has caused concern about his health among his supporters.

It has also started a war of words between his Aam Aadmi Party (AAP), prison officials and Prime Minister Narendra Modi's Bharatiya Janata Party (BJP).

India's financial crimes agency, the Enforcement Directorate (ED), which arrested him, accused Kejriwal of deliberately eating too many mangoes and sweets to spike his sugar levels so that he could use it as grounds to get bail.

Kejriwal and his party strongly rejected these allegations and accused the Tihar authorities of refusing to give him proper treatment which, they said, had led to the spike in his blood glucose levels.

In a letter to the prison authorities on Monday, Kejriwal said he had been demanding insulin for the past 10 days.

"I showed my high sugar levels to every doctor who came to see me. I showed them that there were three peaks in the sugar level every day — between 250-320," Kejriwal said in his letter. Levels below 140mg/dL (milligrams per decilitre) are considered normal.

He added that his fasting sugar level was between 160 and 200mg/dL each day — way above the normal range of 70-100mg/dL.

The prison authorities said Kejriwal was not given insulin as he had not asked doctors for it during a video consultation.

On Monday, a court ordered doctors from Delhi's premier hospital AIIMS to determine his medication, after which he received the insulin jab on Monday evening, AAP spokesperson Pritam Pal Singh told the BBC.

The AAP also accused India's governing Bharatiya Janata Party (BJP) of denying treatment to Kejriwal. "Today it is clear that the chief minister was right he needed insulin. But the officials under the BJP government were deliberately not treating him," AAP leader Saurabh Bharadwaj said in a statement.

The BJP accuses AAP of trying to "generate sympathy" for Kejriwal during the general election which began last Friday and ends in June. "Arvind Kejriwal is a diabetic but his sugar is under control in jail," Delhi BJP president Virendra Sachdeva told NDTV news channel.

Kejriwal is the third AAP leader to be arrested in connection with Delhi's now-scrapped alcohol sales policy in which the AAP government is accused of having favoured liquor barons in exchange for kickbacks.

Kejriwal has called his arrest "illegal" and criticized the investigation, arguing that the ED had failed to frame "specific" charges against him. — BBC