A Missouri prosecutor took his own life inside a county courthouse, forcing investigators to seal the building. 

Platte County Prosecutor Eric Zahnd, 53, was found dead inside the county courthouse on Thursday afternoon, the local sheriff's office confirmed. 

Authorities have yet to provide further details on his passing, with sources telling KCMO that Zahnd died by suicide within the confines of the building. 

Law enforcement said they responded to the courthouse at around 2.15pm on Thursday, the building has since been closed.

Platte County Presiding Judge Myles Perry told Fox4KC that the building would remain closed on Friday and is expected to reopen on Monday. 

Zahnd was the prosecuting attorney in the county since 2002, and had announced in April that he planned to step down from his role at the end of the year. 

He was the longest serving prosecuting attorney in the county's history and was named the state's Prosecutor of the Year in 2014. 

A profile on the county's website said: 'Mr. Zahnd's top priorities are protecting children, prosecuting sex offenders, and cracking down on career criminals.'

Speaking to reporters after announcing his decision to step down, he said that it was the 'right time to step back from public life and just do something else.'

He went on to endorse First Assistant Prosecuting Attorney Mark Gibson to succeed him, who Zahnd had hired in 2004. 

Zahnd also said that he would frequently daydream about life outside of the courthouse, specifically about spending time with his two sons. 

He also played an important role in the passing of Jessica's Law, which was brought in to put child rapists in prison for life. 

He also brought about changes that saw mandatory sentences handed down to convicted internet predators. 

Missouri Attorney General Catherine Hanaway said in a statement: 'I am deeply saddened to learn of the passing of Platte County Prosecutor Eric Zahnd.

'I have known Eric for many years and have always held him in the highest regard. Eric was a true patriot, a person of remarkable character and integrity, and a public servant who cared deeply about his community. 

'We are very grateful for his dedication to public safety, the rule of law, and Platte County.

'My thoughts and prayers are with his wife, Tracy, and sons, Benjamin and Luke, during this incredibly difficult time.'

Tim Garrison, executive director of the Missouri Association of Prosecuting Attorneys, added: 'Eric was a beloved and highly respected member of our association.   

'Eric was a dear friend, mentor, and trusted colleague to prosecutors across Missouri and, through his extensive work with the National District Attorneys Association, across the country. 

'He helped guide many of those serving in the profession today, and generations of Missouri attorneys benefited from his counsel, encouragement, and support.

'Above all, Eric was a devoted husband and father. He often spoke of his family as his greatest accomplishment and took tremendous pride in the life he built with his wife of more than 30 years, Tracy, and their sons.

'Eric’s charisma, intelligence, and warmth were magnetic. It is difficult to put the magnitude of this loss into words. 

'His absence will be deeply felt throughout the prosecutor, law enforcement, and broader public safety communities, and by the many people whose lives he touched.

'Our thoughts and prayers are with Tracy, his sons, and the entire Zahnd family. We hope their privacy will be respected as they grieve this unimaginable loss.'

If you or someone you know needs help, please call or text the confidential 24/7 Suicide & Crisis Lifeline in the US on 988. There is also an online chat available at 988lifeline.org.