A former New York University professor and outspoken advocate for women's empowerment remains behind bars after failing to make $5,000 following her arrest for allegedly stalking and harassing her ex-lover.

Dutch economist and educator Heleen Mees, 44, is accused of sending over 1,000 emails to chief Citigroup economist Willem Buiter - a married father of two - over two years.

Sexually explicit images were also included, according to police and court documents.

However, she remains in prison at Rikers Island after failing to gather the money together yesterday.

Dutch economist Heleen Mees leaves Manhattan Criminal Court after attending court proceedings for her stalking case in New York March 10, 2014

Willem Buiter, married father-of-two and chief economist at Citigroup Inc, was allegedly sent 1,000 emails by Mees over two years

Missives from Mees to the world-renowned economist allegedly contained threats as well as sexually charged language.

'What can I do to make it right? Shall I lick your b***s?' Mees allegedly wrote to her paramour.

In another letter cited by The New York Daily News , the 44-year-old ex-adjunct professor at NYU's Robert F. Wagner Graduate School of Public Service allegedly suggested that she and Buiter adopt a child.

Mees was taken into custody just before noon Monday.

Mees' attorney, Vaneshka Hyacinthe, claimed that her client 'had a long-standing relationship' with Buiter and 'the emails go in both directions.'

A Manhattan judge ordered the 44-year-old economist to avoid all contact with Mr Buiter and his family.

It is believed that the married 63-year-old economist and the Dutch NYU professor once had an intimate relationship, but at some point it ended.

'Hope your plane falls out of the sky,' the embittered Mees wrote to Buiter, according to court documents.

Threatened: Mees allegedly sent harassing messages' to Buiter's wife, economics professor Anne Sibert (pictured), and the couple's two children

Buiter, a native of the Netherlands, is married to economics professor Anne Sibert, and the couple have a 22-year-old son and a 19-year-old daughter.

Mees, who is fluent in five languages, including Mandarin and French, was assistant professor in economics at Tilburg University and a researcher at the Erasmus School of Economics in the Netherlands. Her area of expertise is monetary policy and emerging economies.

It is believed that the brilliant economist and vocal advocate for the advancement of women in the workplace has become obsessed with her distinguished lover.

Court papers filed in the case against Mees paint a portrait of an unhinged woman who bombarded Buiter with a slew of increasingly bizarre and disturbing emails between July 1, 2011 and Monday, including one sent May 3 that included an image of dead birds.

Mees even dedicated her PhD dissertation to Buiter and thanked him for being 'so kind' to meet with her in the summer of 2008 in London, according to the New York Post.

According to the court filings, the 44-year-old alleged stalker also harassed Buiter's wife and children despite her ex-lover's repeated requests that she stop her barrage of messages.

On February 27, Mr Buiter sent Mees a cease and desist letter, but that did nothing to deter the lovesick professor, who proceeded to fire off several hundred more emails to him, according to court documents.

Willem Buiter has chaired the World Economic Forum and was on the Bank of England's Monetary Policy Committee. In 2010, he was hired as Citigroup's chief economist.