An Indian diplomat convicted on charges of passing state secrets to Pakistaninfo-icon's intelligence services has been jailed for three years, her lawyer said on Sunday.

Madhuri Gupta was found guilty in a New Delhiinfo-icon courtinfo-icon on Friday of "spying and wrongful communication of information" while posted to the Indian embassy in Islamabad.

Read more: Pakistan's Intelligence Agenciesinfo-icon: The Inside Story

Gupta, 61, was arrested in 2010 for allegedly passing information to the Inter-Services Intelligence (ISI).

The low-ranking diplomat was detained for alleged breaches of Indiainfo-icon's official secrets act and held for two years before being released on bail. Her lawyer, Joginder Dahiya, said Gupta would appeal against her sentencing in a higher court.

"She has already been in custody for about 21 months. She should have been released on the basis of the time she has already spent in jail," he said.

Gupta avoided more serious jail term because the information she passed to Pakistani handlers in 2009 and 2010 was not related to military, the Press Trust of India reported.

As a second secretary, Gupta was among the lowest ranked officials at the highly-sensitive embassy in the Pakistani capital.

She has always denied the charges and claims she was falsely implicated by embassy and foreign ministry officials with whom she had a strained relationship.

But the court determined that her actions had tarnished India's reputation and compromised its security, handing the maximum possible jail term for the offences.

The information "passed on by the accused (was) categorically sensitive information which could have been useful to the enemy country... and its secrecy was of utmost importance," PTI reported. "Therefore, she does not deserve any leniency in punishment."

Indian police say Gupta had been under surveillance for six months before being taken into custody in 2010.