Investigators have learned there was a romantic relationship between Jeremy Sanchez and the 16-year-old boy accused of killing him

Investigators have learned there was a romantic relationship between a 16-year-old boy and the 17-year-old boy he is suspected of fatally stabbing in suburban Los Angeles, authorities say.

Sheriff's Department spokeswoman Nicole Nishida confirmed the relationship Friday. The two teens had previously been described as very good friends.

Investigators told KCAL9 that Sanchez was killed after telling his boyfriend he wanted to break-up so he could date a girl.

After that talk, the suspect called Sanchez and asked to meet before midnight Tuesday at the riverbed, where Sanchez's body was found stabbed in the bushes.

The body of Jeremy Sanchez was found Wednesday in a riverbed in South El Monte after he failed to show up at school.

The teen's father called the suspect and another good friend of his son to help search for him.

'The person who killed him is the one who said, "Look there he is,"' sheriff's homicide Lt. John Corina said.

Investigators said Sanchez, right, was killed after telling his boyfriend he wanted to break-up so he could date a girl

Thursday morning, detectives received information that the friend might be involved in the incident. They served a search warrant on his home and obtained 'substantial' evidence that led to the teen's arrest.

Lt. Corina would not say whether the suspect confessed to the crime.

Investigators believe the suspect, whose name hasn't been released because of his age, stabbed Sanchez multiple times and left his body in the wooded area.

The murder weapon hasn't been recovered yet, but they believe the suspect used a knife.

Sanchez's cousin, Briana Amigon, said in a post on GoFundMe that he loved playing sports and was on his school's football and wrestling teams.

'We have no words to describe the grief that their family is experiencing right now,' she wrote.

Sanchez's body was found on Wednesday, after father called the suspect and another good friend to look for him. Above, the site where his body was found

Family members are pictured above on Thursday at the spot where Sanchez's body was found

Edward Zuniga, superintendent of El Monte Union High School District, said Sanchez was a popular student athlete and that school officials were in shock over his death. The district offered grief counseling to students, he said.

'Jeremy was a very respectful kid, very outgoing, and always had a smile on his face,' his wrestling coach, Ray Castellanos, said after visiting a memorial set up at the riverbed where he was killed. 'I'm devastated. It's not supposed to be this way.'

The teenage suspect was arrested Thursday when detectives grew wary of his story after hearing conflicting statements during interviews, Corina said.

Sanchez's cousin, Briana Amigon, described the South El Monte High School student as a 'loving young man' who was 'out going and full of energy'. She created a GoFund Me to help pay for the teen's funeral, which has raised more than $14,000 as of Friday.

'He loved playing sports he was on the varsity football team and also on the wrestling team. We have no words to describe the grief that their family is experiencing right now, and many friends and family have asked how they can help at this difficult time. We have set up this Go Fund Me account to help them cover the costs of the funeral service to honor Jeremy Sanchez memory. We thank everyone for their support, prayers and condolences in this difficult time,' she wrote.

Los Angeles County sheriff's Lt. John Corina (left) said detectives suspected the teen was the murder after he gave conflicting stories during interviews

The school also posted a message on its Facebook page offering condolences to Sanchez's family and friends.

'Jeremy was a happy, funny and light-hearted student who had a passion for sports, having played on the football, baseball and wrestling teams. He was a beloved, natural leader on our campus and his death is nothing short of devastating,' the school wrote. 'We are providing grief counselors to students and staff to help them process their emotions during this difficult time.'

Ray Castellanos, Sanchez's wrestling coach, said the teen was a very respectful kid and 'always had a smile on his face'.

'I'm devastated. It's not supposed to be this way,' he said.

Castellanos, who had also coached the teenager's father, said Sanchez was a top athlete on the high school's varsity wrestling team but that he was also dedicated to his schoolwork. He visited the boy's home on Thursday and said his father shed tears as they hugged for several minutes.

Recalling their last exchange, Castellanos told the teenager not to eat junk food because he wanted him to stay a star athlete.

'He said, 'I'm going to be a champion, coach.' Now he'll teach the angels in heaven to wrestle,' Castellanos said.